I don't know what I've done, but I've just come back to my Vuforia Unity project and suddenly the camera is having its projection matrix messed up when I run on the device. The camera is stretching horizontally in a very unpleasant way :)
I can't for the life of me figure out what I must have done. If I comment out the update of the projection matrix in UpdateProjection then it's fine - but clearly that's not something I should be doing.
What might I have done?
It appears that screen width and height weren't the right way around on initialization, but if I wait a bit then they are - however, this doesn't fix the problem. I'm getting a 480 x 360 back from the camera and 960x640 from the screen which maybe something to do with it. Given that the camera is 360 high not 320 as I would expect.